1. Field of the Invention
The present invention relates to a fuel injector, e.g., a high-pressure injection valve for the direct injection of fuel into a combustion chamber.
2. Description of the Related Art
In known high-pressure injection valves, particularly those having multipole preparation, the fuel is sprayed into the combustion chamber through spray orifices and pre-stage chambers. In this context, on the combustion chamber side, the pre-stage chamber ends flush with the end face of the housing of the injection valve facing the combustion chamber. This end face is also known as an injector tip. Each injection leads to a wetting of the region of the end face that is close to the pre-stage region of the end face and to increased particulate emission. In the process, fuel residues polymerize and form a porous layer while merging with the soot particles formed in the combustion chamber. In subsequent injection processes, this porous layer acts like a “sponge” for the fuel and leads to vaporization and particle generation in the vacuum phase subsequent to the compression.